[6a-A203-1~10] 21.1 Joint Session K "Wide bandgap oxide semiconductor materials and devices"

[6a-A203-10] High Performance Top-Gate ZnO TFT Achieved by Post Oxidation and Annealing

〇Kimihiko Kato¹, Hiroaki Matsui¹, Hitoshi Tabata¹, Mitsuru Takenaka¹, Shinichi Takagi¹ (1.Univ. of Tokyo)

Keywords:ZnO, TFT, plasma oxidation

For performance improvement of top-gate thin film transistors (TFTs) with a thin (~10 nm) ZnO channel layer, control of TiN/Al₂O₃/ZnO gate stacks by combination of post plasma oxidation and annealing have been systematically investigated. It is found that control of the ALD-Al₂O₃/ZnO interface is essentially important for superior ON/OFF operation of TFTs. The appropriate combination of post plasma oxidation (PPO), post O₂ annealing (POA), and post metallization annealing (PMA) can realize small subthreshold slope (~120 mV/dec.) and remarkably high field effect mobility (~50 cm²/V·s).